Oral contraceptives and in vivo cytogenetic studies

Cytogenetic studies of peripheral blood lymphocyte cultures were done on 7 young women prior to and after 1 and 2 months of oral contraceptive use. No significant change in chromosome breaks or mitotic index was revealed when each of the 7 women served as her own control nor when findings in 4 additional young women who had been using oral contraceptives for more than 3 years were compared to those from 4 controls. These results differ from several other studies in vivo which did not use each patient as her own control.